package 链表;

public class 合并两个有序链表 {
    public class ListNode {
     int val;
      ListNode next;
      ListNode() {}
      ListNode(int val) { this.val = val; }
      ListNode(int val, ListNode next) { this.val = val; this.next = next; }
  }
  //递归
    public static ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if (l1==null){
            return l2;
        }
        if (l2==null){
            return l1;
        }
        if (l1.val<l2.val){
            l1.next=mergeTwoLists(l1.next,l2);
            return l1;
        }
        else{
            l2.next=mergeTwoLists(l1,l2.next);
            return l2;
        }
    }
}
